Written by Art Reisman
CTO – http://www.apconnections.net
Marketing and hype for services ultimately meet the reality of what is possible. Below, I explain the basic reasons behind what is possible in terms of video on your wired home network and then compare that to the limitations of 3G and 4G service.
In the wired network world, many consumers are connected to their provider via a spoke and hub topology, like this
The hub, “H”, is at your cable operator’s regional office and the spokes are dedicated wires to each home. When supplying video such as Netflix, your cable operator caches popular videos at their HUB, so when you select a movie, it plays unencumbered on a wire direct from the central office to your home. In this topology you are not competing for bandwidth on the last mile. The bottom line is you can watch a good deal of video without interruption.
Yes, it is possible to watch video on your wireless device, but unlike the wired network to your home, claims of high speeds from 4G providers have limitations. Due to the way wireless frequencies operate, the more users on the nearest tower, the more likely your video feed will break up.
With a wireless provider there is also a hub, but unlike the HUB of the wired network, many users share a single wire (Frequency) back to this HUB. Your wireless provider uses time division multiplexing to give each user a slice of the bandwidth on the wire. In the diagram below, there are no dedicated wires to each phone, the lines are a symbolic representation of a slice of time. In other words, the wire back to the High Bandwidth HUB is virtual and only exists for a short moment in time. As you add more and more devices to the wire, each time slice becomes shorter and shorter, and at some point, your time slice will become so small, it will be impossible to watch a video no matter how fast the advertised speed to your wireless phone.
Note: There is variability in the quality of video in the wired model but they are related to where the content is located and not the last mile contention described above.
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